/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.http;

import org.springframework.util.MultiValueMap;
import org.springframework.util.ObjectUtils;

/**
 * Extension of {@link HttpEntity} that adds a {@link HttpStatus} status code.
 *
 * <p>Returned by {@link org.springframework.web.client.RestTemplate#getForEntity}:
 * <pre class="code">
 * ResponseEntity&lt;String&gt; entity = template.getForEntity("http://example.com", String.class);
 * String body = entity.getBody();
 * MediaType contentType = entity.getHeaders().getContentType();
 * HttpStatus statusCode = entity.getStatusCode();
 * </pre>
 * <p>Can also be used in Spring MVC, as a return value from a @Controller method:
 * <pre class="code">
 * &#64;RequestMapping("/handle")
 * public ResponseEntity&lt;String&gt; handle() {
 *   HttpHeaders responseHeaders = new HttpHeaders();
 *   responseHeaders.set("MyResponseHeader", "MyValue");
 *   return new ResponseEntity&lt;String&gt;("Hello World", responseHeaders, HttpStatus.CREATED);
 * }
 * </pre>
 *
 * @author Arjen Poutsma
 * @see #getStatusCode()
 * @since 3.0.2
 */
public class ResponseEntity<T> extends HttpEntity<T> {

    private final HttpStatus statusCode;


    /**
     * Create a new {@code ResponseEntity} with the given status code, and no body nor headers.
     *
     * @param statusCode the status code
     */
    public ResponseEntity(HttpStatus statusCode) {
        super();
        this.statusCode = statusCode;
    }

    /**
     * Create a new {@code ResponseEntity} with the given body and status code, and no headers.
     *
     * @param body       the entity body
     * @param statusCode the status code
     */
    public ResponseEntity(T body, HttpStatus statusCode) {
        super(body);
        this.statusCode = statusCode;
    }

    /**
     * Create a new {@code HttpEntity} with the given headers and status code, and no body.
     *
     * @param headers    the entity headers
     * @param statusCode the status code
     */
    public ResponseEntity(MultiValueMap<String, String> headers, HttpStatus statusCode) {
        super(headers);
        this.statusCode = statusCode;
    }

    /**
     * Create a new {@code HttpEntity} with the given body, headers, and status code.
     *
     * @param body       the entity body
     * @param headers    the entity headers
     * @param statusCode the status code
     */
    public ResponseEntity(T body, MultiValueMap<String, String> headers, HttpStatus statusCode) {
        super(body, headers);
        this.statusCode = statusCode;
    }


    /**
     * Return the HTTP status code of the response.
     *
     * @return the HTTP status as an HttpStatus enum value
     */
    public HttpStatus getStatusCode() {
        return this.statusCode;
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof ResponseEntity)) {
            return false;
        }
        ResponseEntity<?> otherEntity = (ResponseEntity<?>) other;
        return (ObjectUtils.nullSafeEquals(this.statusCode, otherEntity.statusCode) && super.equals(other));
    }

    @Override
    public int hashCode() {
        return super.hashCode() * 29 + ObjectUtils.nullSafeHashCode(this.statusCode);
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder("<");
        builder.append(this.statusCode.toString());
        builder.append(' ');
        builder.append(this.statusCode.getReasonPhrase());
        builder.append(',');
        T body = getBody();
        HttpHeaders headers = getHeaders();
        if (body != null) {
            builder.append(body);
            if (headers != null) {
                builder.append(',');
            }
        }
        if (headers != null) {
            builder.append(headers);
        }
        builder.append('>');
        return builder.toString();
    }

}
